1. Field of the Invention
This invention relates to structures for static eliminating devices.
2. Description of the Prior Art
Static eliminators of the type known as shockproof static eliminators are well known in the art. Typically they comprise a cable having a central conductor adapted to be connected to a source of high alternating voltage (e.g. 4,000-12,000 volts), and a thick electrically insulating sleeve around the cable. Also included are a plurality of conductive members disposed in axially spaced relationship along a portion of the cable, each consisting of a cylindrical electrically conductive band around the insulating sleeve and a conductive needle electrically connected to the band and projecting generally radially outwardly from the cable. The conductive bands capacitively couple the needles to the source of alternating voltage so that ions are formed around the needles. These ions will neutralize static electrical charges adjacent the needles.
In one known embodiment the needles are pressed radially through the walls of the bands to provide electrical and mechanical engagement therebetween. This embodiment requires bands having a substantial wall thickness to mechanically support the needles, however, which results in a static eliminator of an undesirably large diameter for some applications. Also, the insertion of the needles in the bands during production presents a problem due to the difficulty of handling, positioning and pressing in the small needles.
In another known embodiment the conductive band is a vapor coated layer around the insulating sleeve and the static eliminator comprises a thick layer of electrically insulating material around the vapor coated band. The needles are pressed through the insulating material into electrical contact with the vapor coated band so that the insulating layer mechanically supports the needle. While this construction affords a static eliminator of a small physical diameter, it still requires handling and pressing of small individual needles to assemble the static eliminator.